Have you tried Moyer electronics? I think they have older RCA TV parts.
www.moyerelectronics.com
I had one of those early ctc40's years ago. Mine had "new vista color solid state" and "RCA Victor". The secondary control door flipped up at the bottom. My set had a burned yoke and I finally junked it because I never could find a yoke. That was RCA's first solid state color set and needs to be saved if at all possible. I just wish I could go back and save the one I junked as a teenager.